[Insight-users] Image filtering and feature detection-

[Ryan Smith]

Hi Dan-
The white top hat worked great at removing my extra features, and the binary
thresholding cleaned everything else up, however I am still having some
trouble using the ConnectedComponentFilter.  I found this article which is
trying to do exactly what I am attempting:
http://www.itk.org/pipermail/insight-users/2007-January/020532.html

<http://www.itk.org/pipermail/insight-users/2007-January/020532.html>I want
the position and full width half max (FWHM) of each intensity maxima in the
image.  I tried using the connected component filter and got the output
found at the following URL: http://i.imgur.com/TCqL8.png

<http://i.imgur.com/TCqL8.png>It appears each feature is being tagged as
several different features.  Just to confirm I am sending the binary
thresholded image, not the original Gaussian spot image into the
ConnectedComponentFilter.

I feel like I am going down the wrong path here.  I don't necessarily need
to segment my points, I just need to clean up the image (done) and
potentially use techniques such as those in other ITK problems I have read
to find 'seed points' for some region growing algorithms based on the
intensity maxima of my image.  Any thoughts? Thanks in advance-
-Ryan



On Sun, Aug 15, 2010 at 11:22 PM, Dan Mueller <dan.muel at gmail.com> wrote:

> Hi Ryan,
>
> You might consider using the "white top hat" operation to remove the
> background:
>    WhiteTopHat = I - Dilate( Erode(I) )
> where I is the image, Erode is morphological erosion, and Dilate is
> morphological dilation.
>
> You can find an implementation of this operation in:
>    Code/BasicFilters/itkWhiteTopHatImageFilter.h
>
> Once the background is removed, a simple global intensity threshold
> should suffice to segment the spots. The following filters may be
> helpful for that task:
>    Code/BasicFilters/itkBinaryThresholdImageFilter.h
>    Code/Algorithms/itkOtsuThresholdImageFilter.h
>    Code/Review/itkKappaSigmaThresholdImageFilter.h
>
> HTH
>
> Cheers, Dan
>
> On 15 August 2010 23:04, Ryan Smith <ryanleesmith at gmail.com> wrote:
> > Hi-
> > I am attempting to remove the background and detect features in the
> > following image:
> > http://i.imgur.com/wd3Yt.jpg
> >
> > I have a series of images in which the white circular spots travel and
> the
> > white vertical stripes remain stationary.  I would like to apply some
> simple
> > background subtraction to remove the white stripes then autodetect the
> > intensity maxima associated with the circular features.
> >
> > A brief search provided the following results which address similar
> problems
> > using itkConnectedComponentFilter.  Is this what I want after my
> background
> > is subtracted?  Any example code on how to get the location and sizes of
> the
> > components? Thanks in advance-
> >
> > -Ryan
> >
> >
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